Tongue and groove plank



April 29, 1969 v. F. ONJUKKA 3,440,784

TONGUE AND GROOVE PLANK Filed Sept. 30, 1966 PER: Can/417% /l/Ovm HQE/vrs United States Patent O TONGUE AND GROOVE PLANK Veikko F. Onjnkka, Box 5, R.R. 2, Parry Sound, Ontario, Canada Filed Sept. 30, 1966, Ser. No. 583,303 Claims priority, application (7Ianada, Sept. 30, 1965,

941,76 Int. 0.13041 1/10, E04c 1/10, 1/30 U.S. Cl. 52-233 ll Claim ABSTRACT F THE DISCLOSURE A tongue and groove plank for use in mating and inter` This invention relates to a tongue and groove plank construction for use in the building of log walls.

In the construction of summer cottages and the like buildings it has become increasingly popular to employ relatively thick planks having rounded or chamferred edges to simulate an old style log cabin. The corners of such buildings are commonly formed by notching the planks and interlocking the same, one above the other, the planks being laid horizontally in courses somewhat in the manner of bricks. The planks used in this type of construction employ a simple tongue and groove wherein the tongue portion is on the upper edge of the plank and is directed vertically upwards and the groove portion is along the lower edge of the plank and is oriented vertically downwards. In this way, water running down the sides of the building cannot seep in between the planks due to the upward orientation of the tongue. However, it has been found that such water does in fact seep into the cracks and openings between the planks until it reaches the tongue and on these horizontal abutting plank surfaces the water remains for long periods of time without readily -draining off thereby causing decay of the planks and rendering the entire wall construction somewhat damp. In addition, the use of a single tongue and groove in planks which are arranged horizontally on edge without any other form of support so as to form the entire fabric of the building does not result in a completely rigid and stable building and in fact, in many cases it is found desirable to add some additional form of support or framework in the interior of the building thereby substantially detracting from the pleasing appearance of the log type construction.

Accordingly, it is an objective of the present invention to provide a plank construction employing a double tongue and groove providing for multiple insulation from the weather and also providing a more rigid interlocking joint resulting in a stiffer and more stable construction.

More particularly, it is an objective of the present invention to provide a plank construction having the foregoing advantages in which apparent cracks or openings between adjacent planks are sealed thereby improving the appearance of the building which may otherwise be impaired due, for example, to one or more of the planks being warped or being poorly fitted.

The tongue and groove plank of this invention is used in making an interfitting with other such planks to form a structure of weather tight joints. The plank has a pair of upper tongues along the top of the plank and `a pair of grooves along the bottom of the plank. Each upper tongue has three surfaces which are arranged to mate in 3,440,784 Patented Apr. Z9, 1969 three surfaces of each lower groove to provide a water proof seal therebetween.

The foregoing and other objectives will become ap parent from the following description of a preferred embodiment of the invention which is here given by way of example only and with reference to the following drawings in which like reference devices refer to like parts thereof through the various views and in which:

FIGURE l is a perspective illustration of a portion of a typical wall structure formed of planks according to the present invention; and

FIGURE 2 is a greatly enlarged sectional end elevational view of a series of planks as shown in FIGURE 1 along the line 2 2 thereof.

Referring now to FIGURES 1 and 2 it will be noted that the planks 10 according to this preferred embodiment of the invention are intended for use in a horizontal edge to edge relationship for building partitions or walls and the like. 'Referring particularly to FIGURE 2 the planks 10 will be seen to comprise a substantial thickness dimension T and a depth dimension d equal to somewhere in the region of 2T although this relationship is noty critical. In this preferred embodiment the dimensions T and d will be in the region of 2 inches and 4 inches respectively. The planks 10 are defined by parallel side surfaces 11 and along their upper edges are provided with a pair of tongues 12. separated by a longitudinal groove 13, prefen ably formed with substantially parallel side walls 14 spaced apart a predetermined distance a1 and having a predetermined depth B1. Tongues 12 are further provided with outwardly sloping angled side surfaces 15 intersecting the plane of side surfaces 11 at a predetermined angle X degrees.

Along the lower edges of planks 10 there is provided a pair of longitudinal grooves 16 separated and defined by a longitudinal slightly wedge-shaped tongue portion 17 having slightly angled side walls 18 and have a predetermined maximum width 4112. adjacent its junction with the main portion of plank 10 and a predetermined depth B2. The dimension a2 is preferably arranged to be very slightly greater than the dimension a1 of groove 13 and the dimension B2 is preferably very slightly less than the dimension B1 of groove 13 for reasons to be explained hereinafter.

Grooves 16 are further defined by outer outwardly sloping angled side walls 19 the plane of which intersects the plane of side surfaces 11 at a predetermined angle X2. The angle X2 is preferably somewhat less than the angle X1 referred to above for reasons to be described hereinafter. The downwardly directed corners of side walls 19 are preferably -cut off and provided with bevelled edges 20 so as to avoid unnecessarily thin sections of wood which might otherwise be subject to splitting and disfigure the plank as a whole.

In operation, the planks 10` are arranged with their tongues 12 and grooves 13 oriented upwardly and their tongues 17 and grooves 16 oriented downwardly. The planks 10 are interengaged with one another by fitting tongues 17 in grooves 13 and simultaneously fitting tongues 12` within grooves 16 and then applying a compressive force thereto thereby forcing the slightly wider upper portion of tongue 17 into the slightly narrower groove 13 and at the same time forcing tongues 12 and side walls 15 thereof upwardly into grooves 16 interengaging with side walls 19 thereof and forcing the same to spring slightly apart due to the difference in angles of slope thereof mentioned above. In this way, tongues 12 are forced slightly outwardly by the wedging action of tongue 17 within groove 13` and simultaneously they are forced slightly towards one another by the wedging action of side walls L9 against side walls 15. This simultaneous outward and inward wedging action succeeds in providing a waterproof seal, both around the edges of tongue 17 and also around the edges of tongues 12. It will be noted that tongue 17 being of somewhat less depth than the depth of groove 13 can never engage the bottom of groove 13 and thereby prevent the tight interiitting aforesaid. When so erected, droplets of water indicated as W in FIGURE 1 which may accumulate on the outwardly directed side surfaces of planks will run down the side surfaces 11 thereof and, due to the surface tension of water, will run around the bevelled edges 2()l thereof. However, at this point they will then flow onto the lower portions of side walls 15 of tongues 12 and be conducted downwardly onto the next plank 10. Any tendency for the water to creep in between the planks will be prevented both due to the tight intertting of the planks and also due to the fact that the only available path for the water between the planks lies in an upward direction.

It will be understood that this invention therefore overcomes the problem inherent in conventional tongue and groove planking wherein the opening between the planks is in a horizontal plane thereby permitting water to ow between the planks due to surface tension and, also possibly due to being driven by high winds and thereafter to lie on the vertically oriented surfaces of the plank and rot them out over a period of time.

In addition, to the foregoing advantages, it will also be noted that the instant planking provides a much tighter and more rigid wall structure than previous planking constructions. Due to the tight fit between the sloping walls of the tongues fitting into the grooves, and due to the double tongue and groove construction a joint between two successive plank layers is unusually strong in resisting sidewards loads. A wall built entirely of such planks provides a struct-Ural unit which can be suitably supported at the ends by corner posts to provide a dwelling construction suitable for summer cottages and the like without resort to additional stiffening and strengthening members.

Furthermore it should be noted that due to the comparatively large angles leading into the grooves and due to the comparative shallowness of the groove construction a plank section is provided which is comparatively easy to manufacture. Simple rotary cutters can be utilized for fashioning the planks, such cutters being readily available and well known in the art. It should also be noted that the simple plank section permits considerable latitude in selection and maintaining the angles of the groove sides, the only requirements being that the one angle in less than the other as aforesaid.

What I claim is:

1. A tongue and groove plank adapted for use in parallel arrangement, one said plank interfitting above another said plank and comprising:

a plank member in section being of a greater height than width and having a pair of symmetrically arranged side walls;

a pair of upper tongues disposed lengthwise along the top of said plank being defined by planar outer side surfaces, fiat top surfaces, and planar inner side surfaces, said planar outer side surfaces angled inwardly at a predetermined angle X relative to said plank side walls and meeting said side walls at an upper shoulder;

said planar inner side surfaces being parallel to said plank side walls and being connected by a bottom surface to define an upper groove therebetween, and

said vfiat top surfaces connecting said planar outer side surfaces to said planar inner side surfaces;

a wedge shaped lower tongue depending below said plank and located centrally thereof and.extending longitudinally therealong being defined by planar side surfaces angled in a converging wedge shaped manner from top to bottom thereof and a flat end surface connecting said side surfaces, the width of said tongue being greater than the width of said upper groove; and,

said plank side walls extending downwardly from said upper shoulders for the major portion of said plank to lower shoulders and then extending inwardly and downwardly from said lower shoulders to a point above said end surface 4of said lower tongue; and

a pair of lower grooves arranged on each side of said lower tongue having angled inner side surfaces defined by the lower tongue side surfaces aforesaid,

outer side surfaces dening the opposite sides of said lower grooves being angled downwardly and outwardly at a predetermined angle relative to said plank side walls which is less than X, and,

fiat upper surfaces extending between said inner and outer side surfaces of said grooves, whereby when said planks are assembled in said parallel arrangement said converging planar side surfaces of said lower tongue tit within said upper groove and engage said inner side surfaces of said upper tongues while said outer side surfaces of said lower grooves engage said planar outer side surfaces of said upper tongues and said upper side surfaces of said lower grooves engage with said flat top surfaces of said upper tongues thereby effecting a Water proof seal.

References Cited UNITED STATES PATENTS 3,189,950 1/1965 Johnson 52-233 FOREIGN PATENTS 476,660r 9/1951 Canada. 944,089 8/ 1956 Germany. 175,335 1922 Great Britain.

HENRY C. SUTHERLAND, Prima/'y Examiner.

U.S. Cl. X.R. 

